1. Field of the Invention
The present invention relates to telephony and the internet and, more specifically, to a telephone internet service that notifies an internet user of an incoming telephone call and provides the user with the option of receiving the telephone call while still maintaining an internet connection.
2. Background of the Invention
The most common method of internet access by individual and small business subscribers is by computer modem over conventional analog telephone lines. Subscribers connect to internet service providers (ISPs) by dialing access numbers from within communications applications. Once connected to the ISP, subscribers use internet applications, e.g., web browsers, to exchange data with the internet and browse the web.
While connected to the internet, the conventional analog telephone line is dedicated to data exchange between the subscriber's personal computer (PC) and the internet service provider, and as a result, cannot receive any telephone calls. Thus, when the telephone line is being used for internet access, the subscriber frequently misses incoming telephone calls. Several solutions have been proposed to alleviate this problem. However, each falls short of a complete solution.
One solution is to add another telephone line so that one line is dedicated to telephone calls and another line is dedicated to internet access. However, this solution burdens subscribers with the additional costs of another telephone line. In many cases, the relatively short amount of time spent on the internet by the average subscriber does not justify the installation and monthly service costs associated with a second telephone line.
In response to this service gap, telephony providers have turned to internet call waiting services to notify internet users of incoming telephone calls. Internet call waiting services enable subscribers to receive traditional telephone calls while connected to the internet through a single telephone line. These services send an incoming call message detailing calling party information through a pop-up window on the subscriber's computer screen. In response to this message, a subscriber can accept the call, route the call to voice mail, redirect the call to another number, play a message to the caller, or simply ignore the call. If the subscriber accepts the call, the internet call waiting service terminates the internet connection and connects the call to the user's regular telephone. However, subscribers still do not have the ability to use a single telephone line to simultaneously carry on a voice conversation and continue using the internet.
In response to the drawbacks of internet call waiting services, Internet Protocol (IP) telephony service providers, e.g., eFusion, Inc., have developed internet call waiting services that support a conventional public switched telephone network (PSTN) call during an internet session on one telephone line. These services are typically referred to as internet call waiting with voice over internet protocol (ICW-VOIP) services. With this type of service, an internet subscriber can accept an incoming call, carry on a conversation as part of the call, and continue to browse the web during the call. Incoming PSTN calls are forwarded to application gateways that complete the calls through internet connections to the subscriber's personal computer. In addition, subscribers can place outbound calls during an internet session to a conventional PSTN telephone number, complete with Dual Tone Multi-frequency tone generation. The subscriber communicates over the internet to the application gateway, which completes the call using the PSTN.
Although ICW-VOIP services have partially addressed the problems associated with simultaneous telephone calls and internet sessions, these systems fail to efficiently use existing network resources, relying instead on complex software applications layered on top of PSTN and IP network architectures. Such a system is disclosed, for example, in U.S. Pat. No. 5,889,774, which describes an elaborate method of selecting internet/PSTN changeover servers to establish a voice call to a PSTN extension on behalf of a networked client computer. Because these systems must route voice calls through one or more changeover servers to maintain an initial internet connection, the systems suffer from reduced transmission speed, quality, reliability, and security. In packet-switched voice communication, these transmission deficiencies result in perceptible delays and breaks in conversation.
ICW-VOIP service providers have relied on software because of the inability of gateways to support PSTN-to-IP mapping. For example, H.323 gateways are not capable of completing connections between PSTN telephones and personal computers, and do not have standardized interfaces for querying external databases. (The term “H.323 ” as used herein refers to the internet telephony standard for real-time multimedia communications for packet-based networks with which components and communications must comply.) Typically, these types of gateways are engineered specifically for gateway-to-gateway long distance bypass calls, in which subscribers avoid long distance toll charges by routing voice communication over the packet-switched internet. In long distance bypass systems, transmissions are translated between voice circuit-switched and data packet-switched communication at both sides of a communication. The gateways can support IP-to-PSTN communication, PSTN-to-PSTN communication, and IP-to-IP communication, but not PSTN-to-IP. Thus, a gateway cannot receive a PSTN call, map an IP call to the appropriate subscriber, or initiate a call to the subscriber to complete a connection. Some gateways, implemented with different variations of the H.323 protocol, do not even support IP-to-PSTN communication.
In contrast to the inefficient and slow routing of the ICW-VOIP software services and the lack of intelligent functionality of the gateways, PSTN Advanced Intelligent Networks (AINs) offer the ability to quickly route calls and terminate connections based on subscriber information. AIN networks use a complex, high speed, high traffic volume data packet-switched messaging system to provide versatility in the handling of telephone calls. The Advanced Intelligent Network System is described in U.S. Pat. Nos. 5,701,301 and 5,838,774, which are hereby incorporated by reference.
The AIN enables telecommunications call control and database access from any computer or switching system connected to the Signaling System 7 (SS7) network. The Signaling System 7 (SS7) network refers to the current implementation of the Common Channeling Interoffice Signaling control network used in the United States. The Advanced Intelligent Network (AIN) is a standard call control protocol that uses the SS7network for message transport.
AIN infrastructures of the PSTN include service switching points (SSPs), service nodes (SNs), signal transfer points (STPs), and signal control points (SCPs) with databases. An example of a local PSTN structure 102 is shown in FIG. 1a. The signal control point is a computer that holds, accesses, and maintains the database and communicates with the SSP in directing call routing. The database stores subscriber-specific information used by the network to route calls. The SSP communicates with the SCP and queries the SCP for subscriber-specific instructions as to how calls should be completed. The signal transfer point is a packet switch that shuttles messages between the signal control point and the signal service point. The service node is a smart termination that can assess incoming call information and make appropriate connections.
Much of the intelligence and the basis for many of the new enhanced features of the network reside in the local service control point (SCP). As known by those skilled in the art, service control points are physically implemented by relatively powerful fault tolerant computers. Typical implementation devices include the Star Server FT Model 3200 and the Star Server FT Model 3300, both available from Lucent Technologies™. The architecture of these computers is based on Tandem Integrity S2 and Integrity S1 platforms, respectively. In most implementations of a public switched telephone network, service control points are also provided in redundant mated pairs to ensure network reliability.
The service control points maintain the network databases used in providing custom services, such as databases that identify customers requiring particular services. To keep the processing of data and calls as simple and as generic as possible at switches, triggers are defined at the switches for each call. Each trigger is assigned to a particular subscriber line or call, and prompts a query to a service control point. The service control point then checks its database to determine whether a customized calling feature or custom service should be implemented for this particular call, or whether conventional plain dialed-up telephone service (POTS) should be provided for the call. The results of the data base inquiry are sent back to the switch from the SCP. The return message includes instructions to the switch as to how to process the call. The instruction may be to take some special action as a result of a customized calling service or custom feature. If a “continue” message is received at the switch from the SCP, the call is treated as a POTS-type call. The switch will then move through its call states, select the call digits, and may generate further messages that will be used to set up and route the call, as described above.
Despite the benefits of advanced call routing capabilities, AIN networks are limited by the Signaling System 7 communication in their ability to exchange data with other networks, such as the internet. Thus, the benefits of the specialized AIN services have necessarily been confined to the PSTN infrastructure. However, as the internet has expanded and the demand for subscriber access has grown, the need for a capable interface between the IP network and the PSTN infrastructure has become increasingly important. Thus, the inability of conventional systems to seamlessly exchange data across the IP and PSTN networks limits the potential services available to subscribers.
Therefore, there remains a need for a combined IP and PSTN architecture that enables communication between IP and PSTN protocol. Within this architecture, there remains a need for an ICW-VOIP service that avoids the complicated software solutions of the prior art, compensates for the limited communication capabilities of gateways, and provides fast, reliable, and secured voice communication. This service should eliminate the complex process of selecting and engaging internet/PSTN changeover servers and, instead, should take advantage of existing reliable telephone network resources to provide single-line subscribers with the convenience of answering telephone calls while still maintaining internet access. Furthermore, this service should be easily adaptable to accommodate future advances in gateway technology and compatibility.